Water and urban land-use planning in the developing world: a linked simulation-multiobjective approach

Rapid urbanization in the Third World is exacerbating problems of water supply, flooding, and water pollution, as well as rendering more difficult the provision of such basic services as sanitation. Although fundamental to human welfare, these water-related issues seldom play a major role in guiding urban development. This paper is a description of a water resource-constrained, land-use planning model suitable for use in the developing world. The model allocates population among city subareas and specifies the type of sanitary service and level of water supply to be provided. The core of the model consists of a multiobjective optimization component linked to a rainfall-runoff simulation submodel. The program from the optimization model serves as input for the simulation of the flood regime under the given development conditions. Goal achievement is then evaluated, and reformulation of the optimization model is undertaken if desired. Specific applications include the determination of optimal residential-sector expansion, such as the case of locating sites-and-services projects. An example is given using lexicographic linear goal programming.